i7 4790 or i7 8700k

yeah, there would be a bump in FPS for sure. The 8700k is the best gaming chip you can get right now. Yes, others (AMD/Intel 8600k etc) are close, but the 8700k is awesome. It will push more FPS out of your 1080ti. No doubting that. How much varies from game to game. I’m not sure even with an 8700k you will hit 144hz/fps at 1440p, some games yes CS:GO, maybe fortnight, less demanding games. Games like BF1/BF V maybe not 144hz unless you dial back settings a little. But certainly the 8700k will give you max FPS at that res. I’d go for it considering you have the monitor and the GPU to do it. Something like this would get you started: PCPartPicker part list / Price breakdown by merchantCPU: Intel – Core i7-8700K 3.7GHz 6-Core Processor (£439.94 @ AWD-IT) CPU Cooler: Noctua – NH-D14 65.0 CFM CPU Cooler (£64.99 @ CCL Computers) Motherboard: Gigabyte – Z370 AORUS Gaming K3 (rev. 1.0) ATX LGA1151 Motherboard (£117.54 @ Aria PC) Memory: Patriot – Viper 4 16GB (2 x 8GB) DDR4-3000 Memory (£130.67 @ Amazon UK) Total: £753.14 Prices include shipping, taxes, and discounts when availableGenerated by PCPartPicker 2018-10-07 16:16 BST+0100Providing you have a decent PSU to drive the system, a case to house it all. Edit: update to include a z370 mobo, somehow clicked on a B360, which will work with the CPU but won’t allow OC’ing. Z370 is the way to go with a ‘k’ chip.